Field of the Invention
The present invention relates to a circuit board incorporating a semiconductor IC and a manufacturing method thereof, and particularly to an ultrathin circuit board incorporating a semiconductor IC and a manufacturing method thereof.
Description of Related Art
In a typical printed-circuit board, a plurality of electronic devices such as semiconductor ICs are mounted on a surface of the circuit board. The electronic devices mounted on the circuit board are electrically connected to one another through a wiring layer provided inside the circuit board. In a typical printed-circuit board, however, it is difficult to make thinner because a semiconductor IC is mounted on a surface of the circuit board. Therefore, as for a printed-circuit board for devices that are required to be thin, such as smartphones, a semiconductor IC is not mounted on a surface of the circuit board but embedded within the circuit board made of resin (See Japanese Patent Application Laid-Open No. 2002-246761).
However, in a circuit board incorporating a semiconductor IC disclosed in Japanese Patent Application Laid-Open No. 2002-246761, a semiconductor IC is housed in a concave section that is provided in a core layer of the circuit board. Therefore, the core layer exists even below the semiconductor IC. As a result, it is difficult to make the circuit board thinner as a whole. One possible way to make the circuit board thinner as a whole is to remove the core layer below the semiconductor IC. In this case, however, it is impossible to appropriately hold the semiconductor IC.